Apr 01, 2011People don't always take their pills as prescribed, which can be a big problem when pharmaceutical companies are testing new drugs. Accurate information is essential to determine whether a medication works well when taken as directed. Several companies have tried using RFID to track drug compliance, but most record only when someone removes a pill from a box or blister pack, not whether the drug is consumed.
Now, Maysam Ghovanloo, director of the GT-Bionics Lab and an assistant professor in the school of electrical and computer engineering at Georgia Institute of Technology, has developed a system called MagneTrace that tracks pills as they're swallowed. The system uses a necklace that contains magnetic sensors and an RFID reader designed to detect an ingestible RFID transponder inside a capsule. "The magnetic sensors are very sensitive," Ghovanloo says. "They are used in GPS devices to sense the Earth's magnetic field, and because GPS devices are very popular, the sensors are inexpensive."
The pill containing the tiny transponder also carries a trace of magnetic material. When the capsule is swallowed, the sensors in the necklace detect the change in the magnetic field around the neck area and turn on the RFID reader. The reader picks up the unique ID of the RFID transponder inside the pill. The RFID tag can store drug type, dosage, manufacturer and related information.
The data can be transferred from the necklace to a smart phone using a short-range proprietary communications protocol. If the data doesn't have to be collected and analyzed quickly, it can be stored on the RFID reader in the necklace and downloaded when the patient visits a clinic.
"One difference between our approach and another ingestible RFID pill is we are able to use off-the-shelf transponders, rather than something customized," Ghovanloo says, "so the solution will be less expensive."
Ghovanloo and his team have been testing a prototype system using PVC pipe; they can read the data from the pills going down the pipe consistently. The next step is to get funding for a small-animal trial.
"The big benefit from our approach is the reliability of the data," Ghovanloo says. "The existing method of asking volunteers to keep a diary of when they took pills is highly unreliable. Our system will reduce the need to do multiple trials and allow pharmaceutical companies to use smaller samples because data is more reliable. That should reduce the cost of trials."